The present invention is directed to cleaving of fiber optic elements, and more particularly to an improved method and tool which are especially useful in cleaving fiber optic elements preparatory to subsequent splicing thereof.
In the field of fiber optics, it is often necessary to join or splice together two optic elements by abutting the ends thereof to provide a high efficiency, light coupling therebetween. An inherent problem which has existed in this field involves the achievement of extremely accurate axial alignment between the abutting ends and the achievement of clean, mirror-type surfaces for the ends of the optical fibers. For example, it is ideal that the ends of the optical fibers be cleaved or cut so that the end surface is precisely perpendicular to the longitudinal axis of the optical fiber, although up to a three degree variation is tolerable. Additionally, the end surface is ideally mirrored and extremely smooth and polished, as opposed to having a "mist" type surface, a "hackled" type surface or a spurred end. With these latter types of surfaces and ends, it is necessary to polish the end surfaces to provide for an effective and suitable end surface for splicing. The achievement of these desired objectives are further complicated by the extremely small nature of the optical fibers, the thickness of which often approximates that of a human hair.
One prior art method of cleaving fiber optic elements preparatory to a splice has been to prestress the fibers with a weight and then transversely scribe a small notch in a portion of the surface thereof perpendicular to the longitudinal direction of the fibers. The prestressing serves to cause a failure of the fiber optic element at the location of the notch. The prestressing, for example, may be accomplished by attaching a small weight, for example on the order of 150-200 grams, to the end of the fiber optic element and passing the weight over a pulley or wheel. A suitable cutting tool, for example a diamond tipped cutting element, can then traverse across the upper surface of the element to cut the notch therein.
Another prior art method has been to clamp a fiber optic element with a pair of clamps and then move a cutting tool across a portion of the surface thereof to form a small notch therein, as with the above noted method. Then, one of the clamping elements is moved in a longitudinal direction to stress the fiber optic element in straight tension at the location of the groove or notch.
Another prior art technique for cleaving a fiber optic element has been to arrange two electrodes on opposite sides of the fiber optic element and apply a potential thereto to circumscribe a groove in the element by erosion. However, such a technique is very complex, is somewhat more dangerous in view of the fact that an electric arc is used, further has resulted in variable discoloration of the element and further still, might possibly weaken the fiber optic element.